Korky 528 Anti-Siphon Noise... "TUKATUKATUKATUKA"

We have a Korky 528 Anti-Siphon on our toilet, and it recently started making a noise that sounds like a mix between something going "tukatukatuka" and a steam locomotive barreling down the rails. I'm not sure what's wrong, and strangely enough Googling "Korky 528 anti-siphon tukatuka" doesn't exactly come up with any great results. Any help? You can hear it throughout the house it's so loud.

I'd check three things: first, check your house's water pressure, then, remove and check the cap seal, then make sure that the refill hose is properly attached to the clip above the top of the overflow tube.

You might also verify that the float moves freely. The reason to check the house's water pressure is a toilet valve is probably one of the weakest things, and if the pressure is excessive, it can open on its own, momentarily release the excess pressure, then close, then open again. The pressure should be below 80psi.

It seems like if I push down on the entire mechanism, the noise stops. At one point while I was monkeying around with it, bubbles started coming out near the base of the tube the mechanism sits on top of. Could a bad seal down there cause it to happen?

I have five of these in our house, and so are familiar with them. They're actually a very simple valve design with a minimum of working parts, and usually can be fixed with just some easy service you can do at home.

For your specific problem, that noise, first check and make sure that your water supply knob is turned all the way open.

Then, if that doesn't solve it, time to service the valve. What you are going to do is turn off the water, pull the refill hose off the valve with one hand while you steady it with the other (and don't twist the valve; you can twist the hose to remove it). Then, pull the (white or blue or green or silver) cover off the valve, pinch the little arms attaching the float to the valve cap like you're pinching tweezers, and lift it straight up and off. Then, holding the valve body with one hand so you don't inadvertently unlock it, twist the little cap off counterclockwise 1/8 turn, remove it, turn it over and look at the pink diaphragm in it. Are there blisters? Is there gunk in it? If gunk, give it a good rinse off. If blisters or it looks worn or you can't push on it around the little black pin, you can replace it with the Korky R528 cap, available at Lowe's and many local hardware stores for less than $3. Then, under the cap there is a long tube attached to a round top. Pull that straight up and out. On the bottom of the black tube is a white plastic filter. Pull that out, either by hand or with a needle-nose. Rinse everything. You have now basically seen all the working parts of the valve; the only moving parts are that float and the pink diaphragm, which is why it is so easy to service.

Ah, I forgot to add. Even if the diaphragm isn't perfect, rinse everything off and reassemble the valve and see how it goes. That may fix it for now before you need to go buy one of those caps. Then get the R528 next time you are at Lowe's or equivalent, and change that out at your leisure.

I have given you the basics on the truly important stuff, but here are some reference materials that have illustrations, and even a video:

Also, for what it's worth, you can always call Korky. They will actually walk you through solving any problem and are very, very nice. Their website, which has a phone number, is www.korky.com. Nice web site, but if you want to call them ever, the customer service phone number is 1-800-lavelle. (Lavelle Industries makes Korky products.)

It seems like if I push down on the entire mechanism, the noise stops. At one point while I was monkeying around with it, bubbles started coming out near the base of the tube the mechanism sits on top of. Could a bad seal down there cause it to happen?

Great. Our pleasure. Do look at the video because it's only like 2 minutes long and it does clarify a lot of what I suggested. One thing: the video says you need to replace the cap if the diaphragm doesn't "move freely" around the black pin in the cap, while a woman's finger is swirling around it. That suggests that the diaphragm turns within the cap. It doesn't; it's affixed to it. The swirling finger was meaning to say you should just touch it and make sure there's no gunk on it. Move freely means move freely in and out when you push on it. They are going to correct this, and agree that it's a little confusing wording.

And we always appreciate hearing that you got back in business. So let us know how you made out. I think you're going to find that this was amazingly-easy and quick -- like less than 5 minutes -- even though we are throwing all sorts of new nouns at you and giving you detailed instructions about twist this and rinse that. Also, once you do it once and see how easy it is (and now understand what's going on in that mysterious thing in your toilet), it might give you a little feeling of accomplishment and the desire to tackle any other little similar problems you experience with toilets, faucets, etc.

That Korky web site is a great resource about other products to address issues in other parts of your toilets as they arise, and we're always here with recommendations and help.

By the way, because you may not know this, that valve can be adjusted in height up and down (with the water off) by twisting it counterclockwise so it unlocks and then pulling it up or pushing it down; that's how you adjust the water level in the tank, by moving the head of the valve up or down. This is why we're constantly-saying to hold it in one hand while you're doing something to it with the other: so you don't inadvertently unlock it, have it move, and then wonder where it was supposed to go. (Of course, there are easy ways to figure how high you wanted the water level to be...you just find that height, twist it back clockwise, and it's locked in place again. There's also a little plastic anti-tamper key that folks sometimes install to keep it from unlocking, but most of us don't bother with it. If you actually want to move the valve up and down and it won't turn counterclockwise, the little white triangular key that the installer attached to the pegs is what is preventing it from doing that, and you can just pull the key off.)

And, for what it's worth, don't worry that you're going to break that valve. Even if you were to snap it in half, which you would have to try hard to do, you can get a whole new one at Lowe's for $9, and a first-timer can swap it out in under ten minutes after reading the detailed instructions and watching Korky's video on how to install a new valve. The neat part about servicing it is that you realize how simple and elegant a design it is, and how with the ability to replace that $3 r528 cap, the valve you have in there should just keep going and going.

Well, I took the cap off, rinsed it off, and put it back on. It looked like it was curling up on the sides, so I'm planning on going to buy a replacement today or tomorrow. But for now the noise seems to have stopped. Thanks so much for all of your help!